Contact index system for an electric watch



1964 K. H. SCHOENROCK 3,

CONTACT INDEX SYSTEM FOR AN ELECTRIC WATCH Filed Oct. 12, 1960 3 Sheets-Sheet l Hllllmu m"...

INVENTOR lnrwilz fifiSahaenraclg BY aw ATTORNEYS Oct. 6, 1964 K, H. SCHOENROCK 3,151,440

CONTACT INDEX SYSTEM FOR AN ELECTRIC WATCH 3 Sheets-Sheet 2 Filed Oct. 12, 1960 INVENTOR lmnethlz. iclwemc];

ATTORNEYS 06h 1954 K. H. SCHOIENROCK 3,151,440

CONTACT INDEX SYSTEM FOR AN ELECTRIC WATCH 3 Sheets-Sheet 3 Filed Oct. 12. 1960 INVENTOR .Kzme th ESclzoenmclg BY y fig ATTORNEYS United States Patent Office 3,151,440 CONTACT INDEX SYSTEM 150R AN ELECTRIC WATCH Kenneth H. Schoenrock, Rheems, Pa., assignor to Hamilton Watch Company, Lancaster, Pin, a corporation of Pennsylvania 7 Filed st. 12, 1960, er. No. 62,261

(Ilaims. (CI. 5823) This invention relates to battery operated electric watches and more particularly relates to an improved contact and index system for such watches.

In electric watches of the moving coil type which have been proposed and in the commercial electric wrist watch of the assignee of the instant invention, it is customary to provide periodic energization to the coil by means of some type of spring-type commutating system. One such system is illustrated in assignees patent to J. A. Van Horn et al., No. 2,806,908. The proper operation of this type of contact system is absolutely essential to the successful performance of a Watch and it has been found that some criticality of adjustment exists. Other systems, such as that disclosed and claimed in copending application No. 792,614 of I. H. Reece, filed February 9, 1959, now Patent No. 3,016,685 have completely eliminated this type of spring-type contacting system and utilize the indexing function of the balance wheel to perform the switching operation during the time that it indexes.

In this latter type system, a contact carried by an index roller on the balance staflt forms a circuit with a contact wheel when the balance staif oscillates in one direction. The opposite side of the contact is provided with a jewel pin or other non-conductor which does not form a circuit with the contact wheel when the balance staff oscillates in the opposite direction. The circuit to the battery in this type system is completed through the index pivot which must therefore be composed of some good conducting material.

According to the present invention, it has now been found that it is possible to provide a contact-indexing system in which no insulator need be provided on the contact pin and in which the circuit is not completed through either of the index pivots, thus allowing both of them to be made of steel. In addition, the present system eliminates contact bounce-off which occasionally occurred in prior systems when the contact pin engaged the teeth of the contact wheel.

It is accordingly a primary object of the present invention to provide an improved contact-index system for an electric watch.

It is another object of the invention to provide an improved contact and index system for an electric watch of the type utilizing the oscillation of the balance stafi to impart one way motion to an index wheel wherein the energy required to advance the index wheel is also utilized to provide the periodic electric contact.

It is a further object of the invention to provide an improved contact and index mechanism for an electric watch wherein a contact nib is used to complete the electric circuit.

It is another object of the invention to provide an im proved contact and index mechanism for an electric watch wherein contact duration and contact phase can be altered by adjusting a contact nib.

It is another object of the invention to provide an improved contact and index mechanism for an electric watch wherein initial contact bounce-off is eliminated.

poor conducting material.

T hose and further objects and advantages of the present invention will become more apparent upon reference to the following specification and claims and appended drawings wherein:

FIGURE 1 is a partial vertical section of an electric watch showing the combined contact and index system of the present invention;

FIGURE 2 is a diagrammatic plan view showing the combined contact and index system in a rest position;

FIGURE 3 is a diagrammatic plan view showing the index and contact system of the present invention in the contact making position; and

FIGURE 4 is a diagrammatic plan view showing the contact and index system of the present invention in the contact breaking position.

Referring to FIGURE 1, a balance stafi 2 is mounted by means of suitable pivots 4 and 6 in a bridge and pillar plate, not shown. The balance staff 2 carries a balance wheel 2i on which there is mounted a coil 22 of the gen eral type shown in the before mentioned Van Horn et a1. Patent 2,806,908. One end of a hairspring 8 is attached by a suitable screw 12 to a collar 10 mounted onthe balance staff, the other end of the hairspring being fastened 1 to a hairspring stud 14 by a screw 16. Also attached to the balance staff 2 is a contact roller 28.

A generally rectangular contact pin 30 is mounted in the contact roller and extends downwardly below the lower surface thereof. The contact pin is electrically insulated from the contact roller by means of suitable insulation 34 and is electrically connected to the coil 22 by a suitable wire 32. Although the pin is rectangular in the preferred embodiment, it could take any desired configuration. The insulation 34 may be of any suitable type, an expoxy adhesive being convenient.

The pillar plate and a train bridge, not shown, support bearings 38 and 40 of an index assembly shown generally at 36. This index assembly consists of an index pinion 42 and an index wheel hub 44 mounted on a staff 26. The index hub is made of any suitable metal and is electrically insulated from the index pinion staff by any suitable material 50, such as an epoxy resin.

Mounted on the hub 44 is a contact wheel 46 and an index Wheel 48. The contact wheel is constructed of an electrically conductive material and is provided with a plurality of unsymmetrical teeth around its periphery. The index wheel is constructed of any suitable material and is provided with a plurality of symmetrical teeth around its periphery. In the preferred embodiment, the contact wheel takes the shape of a saw-tooth wheel and the index wheel takes the shape of a star wheel, but any suitable shapes could be used. The teeth of the contact wheel and. the teeth of the index wheel are staggered so that the teeth of the index wheel protrude between the teeth of the con-tact wheel as is best seen in FIGURES 2-4. An index magnet 52 is provided in a known manner to serve as a detent for the index wheel 48.

A contact staff 54 is suitably mounted in the pillar plate a and a bridge by means ofpivots 56 and 58. The con Patented Get. 6, 1964 3 tact staff 54. Movement of the contact nib in a clockwise direction is restrained by a banking ewel pm 62.

This pin is preferably formed with an eccentric mount ing stud 64 so that when the stud 64 is received in the watch frame rotation of the pin 62 will permit adjustment of the angular distance that the contact nib oil can travel in the clockwise direction.

The contact stafl also carries a collar as to which one end of a contact positioning hairspring 68 is attached by a suitable screw 79. The other end of the contact positioning hairspring 68 is fastened to a stud '72 mounted on the frame of the watch. spring acts to bias the contact stall in a clockwise direction, and thus hold the contact nib 6t) against the pin 62. The stud 72 is insulated from the frame of the watch and is electrically connected to the positive terminal of a battery 76.

The electric circuit for the watch can be traced from the positive side of the battery '76 to the stud 72, and. through the contact positioning hairspring 68, contact collar 66 and contact staff 54 to the contact nib 68. When the contact wheel engages the contact nib 6d, the circuit is completed through the contact wheel 46, the contact pin 30, lead 32, the coil 22, the balance wheel 2%, the balance staff 2, the balance collar 10, the balance hair spring 8 and the stud 14 to the negative side of the battery 76. The circuit to the coil can thus be broken in two places, at the contact pin 3% and at the contact nib 68, instead of in the single place common in prior elmtric watches.

Referring now to FIGURES 2, 3 and 4, the operation of the above described system will be discussed. In Fl"- URE 2, the contact wheel and index wheel are seen in the rest position, that is, the position in which the contact pin 30 carried by the contact roller 23 has just contacted the contact Wheel 46 due to the counterclockwise rotation of the balance stair" 2. In this position, although the contact pin 39 has engaged the contact wheel 46, the electrical circuit is not complete because there is a break between the contact wheel and the contact nib.

Referring to FlGURE 3, the balance staff 2 has continued to rotate in a counterclockwise direction so that the contact pin 3t engaged with one of the teeth 76 of the contact wheel 46 has started the clockwise rotation of the contact wheel 46. In this position, one of the teeth of the contact wheel 46 engages the notched end 84) of the contact nib 60 and completes the electrical circuit, thus energizing the coil 22. The engagement of the contact wheel tooth with the contact nib 69 causes the contact nib 60 to rotate in a counterclockwise direction away from the banking jewel pin 52. and against the force of the contact positioning hairspring 68.

Referring to FIGURE 4, the contact pin 30 has rotated the contact wheel 46 as far as possible before disengaging. At this point, the tooth of the contact wheel 46 has disengaged the contact nib 60 which has returned, under the influence of the contact positioning hairspring 6%, to its rest position against the banking jewel pin 62. At this time, the contact wheel 46 has caused the rotational movement of the index assembly through an angle suificient to place one of the teeth of the index wheel 43 within the attractive magnetic field of the index magnet 52. This magnetic attraction continues the rotation of the index wheel 48 until the tooth thereon is centered directly above the index magnet 52. The magnetic attraction thus prevents any further clockwise rotation of the index assembly.

After the balance stall 2 has completed its counterclockwise oscillatory motion, it reverses direction and the contact pin 3% again comes into contact with the leading edges of another of the of the unsymmetrical teeth 76 of the contact wheel 46. As the contact pin 30 slides along this leading edge, it causes the contact wheel 46, and thus the index assembly, to rotate counterclockwise through a small angle against the force of the magnetic The contact positioning hair- 7 4 attraction between the index wheel tooth and the index magnet 52. The rotational angle through which the index assembly moves is not sufficient, however, to bring a contact tooth 76 back into contact with the notched end 39 of the contact nib il, and therefore the circuit remains open.

It can be seen from the above description that the electrical aberrations resulting from initial contact bounce-off is eliminated since initial impact and bounce-off ternn'nates before the circuit is completed by the tooth of the contact wheel engaging with the contact nib. Since neither the index nor contact bearings are parts of the electrical circuit, they may be made of. steel or some other poor conducting material. The use of an insulating portion on the contact pin 39 is eliminated because the circuit is broken on the back swing of the balance staff at the contact nib. Both the initiation of coil energization and its duration may be controlled by rotation of the banking jewel pin 52.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A contact indexing device for an electric watch comprising a balance staff, a roller carried by said balance stall, an electrical contact pin mounted on said roller, a toothed index wheel, a toothed contact wheel mechanically coupl d to said toothed index wheel for rotation therewith, said contact wheel being engaged by said contact pin upon rotation of said balance staff to cause rotation of said wheels, detent means cooperating with the successive teeth of said index wheel to arrest the rotation of said Wheels, a pivotall mounted electric contact having a rest position spaced from and intermediate the teeth of said contact wheel, said pivotally mounted contact being movable by a tool of said contact wheel substantially tangentially of said contact wheel until it disengages from said tooth and resilient means urging said pivotally mounted contact back into said rest po sition whereby said pivotally mounted contact is engaged by a tooth of said contact wheel only during a portion of the rotational movement of said contact wheel.

2. A device according to claim 1 wherein said wheels are mounted on a common shaft, the teeth of said wheels being in staggered relation to one another.

3. A contact-indexing device for an electric watch comprising a balance staff, a roller carried by said balance staff, an electrical contact pin mounted on said roller, an electrically conductive contact Wheel having unsymmetrical teeth, an index wheel having symmetrical teeth, said wheels being mounted on a common shaft with their teeth in staggered relation, said contact pin engaging a lagging edge of one of said teeth of said contact wheel when said balance staff rotates in one direction to cause rotational motion of said wheels, detent means cooperating with the successive teeth of said index wheel to arrest the rotation of said wheels, a pivoted electrical contact nib having one end rotatable into a rest position spaced from and intermediate the teeth of said contact wheel when movement of said wheels is arrested by said detent means, said end of said contact nib being movable by a tooth of said contact wheel sixstantially tangentially of said contact wheel until it disengages from said tooth, and spring means urg ng said end of said contact nib into said rest position whereby said end of said contact nib is engaged by a tooth of said contact Wheel only during a portion of the rotational movement of said contact Wheel.

6 Beyner Dec. 24, 1957 Rawlings et a1 Apr. 29, 1958 Beyner Aug. 5, 1958 Gerhard Aug. 16, 1960 FOREIGN PATENTS Switzerland Aug. 31, 1959 Germany June 14, 1933 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 151M140 October 6 1964 Kenneth H Schoenrock It is hereby certified that error appears in, the above numbered-patent requiring correction and that the said Letters Patent should read as correctedbelow.

Column 3 line 71 strike out "of thefl first occurrence; column 4 line 43, for "tool" read tooth -=o Signed and sealed this 27th day of April 1965.

(saw Attes t:

ERNEST W. SWIDER I 1 EDWARD J. BRENNER At u asting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 151 44O October 6,, 1964 Kenneth Ho Schoenrock It is hereby certified that error appears in the above numbered-patent requiring correctionand that the said Letters Patent should reecl a1s corrected below,

Column 3 line 71 strike out "of the" first occurrence; column 4 line 4L3, for "tool" read tooth Signed and sealed this 27th day of April 1965,

(SEAL) A-ttest:

ERNEST W. SWIDER' EDWARD J. BRENNER Attcsting Officer Commissioner of Patents 

1. A CONTACT INDEXING DEVICE FOR AN ELECTRIC WATCH COMPRISING A BALANCE STAFF, A ROLLER CARRIED BY SAID BALANCE STAFF, AN ELECTRICAL CONTACT PIN MOUNTED ON SAID ROLLER, A TOOTHED INDEX WHEEL, A TOOTHED CONTACT WHEEL MECHANICALLY COUPLED TO SAID TOOTHED INDEX WHEEL FOR ROTATION THEREWITH, SAID CONTACT WHEEL BEING ENGAGED BY SAID CONTACT PIN UPON ROTATION OF SAID BALANCE STAFF TO CAUSE ROTATION OF SAID WHEELS, DETENT MEANS COOPERATING WITH THE SUCCESSIVE TEETH OF SAID INDEX WHEEL TO ARREST THE ROTATION OF SAID WHEELS, A PIVOTALLY MOUNTED ELECTRIC CONTACT HAVING A REST POSITION SPACED FROM AND INTERMEDIATE THE TEETH OF SAID CONTACT WHEEL, SAID PIVOTALLY MOUNTED CONTACT BEING MOVABLE BY A TOOL OF SAID CONTACT WHEEL SUBSTANTIALLY TANGENTIALLY OF SAID CONTACT WHEEL UNTIL IT DISENGAGES FROM SAID TOOTH AND RESILIENT MEANS URGING SAID PIVOTALLY MOUNTED CONTACT BACK INTO SAID REST POSITION WHEREBY SAID PIVOTALLY MOUNTED CONTACT IS ENGAGED BY A TOOTH OF SAID CONTACT WHEEL ONLY DURING A PORTION OF THE ROTATIONAL MOVEMENT OF SAID CONTACT WHEEL. 